The present invention broadly relates to dispensing containers and, more specifically, pertains to a new and improved construction of a dispensing container for a highly viscous filler material or package component and to a new and improved construction of an expulsion device for such dispensing container.
Generally speaking, the dispensing container of the present invention comprises: a cartridge containing the highly viscous filler material, the cartridge having a forward end and a rear end and defining a longitudinal direction; the forward end being provided with a dispensing orifice for the highly viscous filler material or package component; the cartridge comprising a longitudinally translatable piston for expelling the highly viscous filler material or package component; an adapter for a conventional pressurized gas container sealingly fastenable to the rear end of the cartridge, the adapter sealingly closing the rear end of the cartridge and defining conjointly with the piston a pressure chamber devoid of the highly viscous filler material or package component; the dispensing container defining a forward direction and the adapter being structured to connect a conventional pressurized gas container with the pressure chamber for generating a pressure cushion or pressure charge active upon the piston for driving the piston in the forward direction.
The expulsion device of the present invention is intended for a dispensing container for a highly viscous filler material or package component. This dispensing container is in the form of a cartridge having a rear end and a piston moveably arranged therein and comprises: an adapter for a conventional pressurized gas container and sealingly fastened to the rear end of the cartridge; the adapter accommodating the conventional pressurized gas container, sealingly closing the rear end of the cartridge and defining conjointly with the piston a pressure chamber devoid of the highly viscous filler material or package component; the expulsion device defining a forward direction and the adapter being structured to connect the conventional pressurized gas container with the pressure chamber for generating a pressure cushion or pressure charge active upon the piston for driving the piston in the forward direction.
Numerous highly viscous or pasty products such as caulking compounds, putties, adhesives and the like are now packaged in cartridges. Standard cartridges are cylindrical containers provided with a usually conically convergent application orifice at their forward end and closed at their other end by a movable piston. For removing the product from the cartridge, the cartridge is inserted into an application device by means of which the piston is either manually or pneumatically pressed forward, thus expelling the product.
The manually operated application devices work in discrete portions and therefore do not permit a uniformly continuous bead or strand of product. Furthermore, the requisite piston rod can be disturbing and the manual pumping can often lead to rapid fatigue.
The pneumatic application devices do not exhibit these disadvantages but are relatively complicated in design and are dependent upon a compressor or the like, so that they remain practically exclusively reserved for professional usage.
A cartridge package is also known, for instance, from the U.S. Pat. No. 3,568,892, granted Mar. 9, 1971, in which the cartridge containing the filler material is clamped in a holder analogous to the situation in the above-mentioned manually operated packages. In contradistinction to the latter, an aerosol pressure container is provided in this package which generates a pressurized gas cushion between the cartridge piston and a support plate of the holder sealingly closing the end of the cartridge. This pressure cushion bears upon the piston and thereby drives out the filler material. The supply of pressure medium from the pressure container into the pressure chamber between the cartridge piston and the support plate is controlled by a trigger mechanism acting upon the pressurized container or its valve.
This known cartridge package is relatively complicated in design for a mass-produced product and furthermore does not permit stopping the dispensing of filler material as long as the pressure cushion is still strong enough to drive the piston forwards in the cartridge.
A further pressurized gas-actuated cartridge package is known, for instance from the U.S. Pat. No. 3,217,932, granted Nov. 16, 1965. In this package, the cartridge is not situated in a holder of its own, but the aerosol pressure container is fastened to the rear end of the cartridge by means of a special adapter. A threaded nipple is provided in the adapter upon which an appropriately formed valve component of the pressure container can be screwed, thereby sealingly connecting the pressurized container to the cartridge and fixing it thereupon, while a pressurized gas cushion simultaneously is formed in the rear end of the cartridge which acts upon the cartridge piston and drives the latter forward as long as a special application valve screwed onto the forward end of the cartridge is open.
In this known cartridge package the control of the dispensing of the product is therefore effected via the application valve and the cartridge is constantly under service pressure. The latter is disadvantageous for various reasons. Furthermore, this known cartridge package is still relatively complicated in design.
Other constructions of dispensing devices are exemplified by U.S. Pat. No. 3,250,443, granted May 10, 1966 and U.S. Pat. No. 3,367,545, granted Feb. 6, 1968.